The most common examples of spills cleansed by this invention are petroleum hydrocarbons spilled on bodies of water in harbors, lakes, rivers and oceans. This patent discloses a product and process for disposal of toxic liquids and/or suspensions that may be absorbed on an organic substrate and disposed of in situ, specifically a waste agricultural product that has been processed for the above purpose. Cotton gin trash (also called cotton gin waste) is the residue remaining from the mechanical separation of cottonseed from its lint by a cotton gin. (Cotton Ginners Handbook, Agricultural Handbook No. 503, Agri. Res. Ser. U.S.D.A. 1977, pages 80-81). In the United States cotton is harvested by mechanical pickers and considerable plant debris of many kinds is also collected along with the cottonseed. After the seed and mass of plant debris has passed through a cotton gin to remove the seed and lint the trash is dried to 5-20% by weight moisture. It absorbs oily liquids such as petroleum hydrocarbons and grease on water surfaces and may be disposed of by leaving the unwanted substance soaked in gin trash to biedegrade in the water. The microflora contained in the gin trash biodegrades the unwanted substance, in situ, to harmless residues. The process is known as mineralization.
Accidental spills of petroleum hydrocarbons and similar hazardous liquids frequently occur on bodies of water. A thin film is usually first formed; difficult to remove by any means. In working with cotton gin trash for cleansing spills of hazardous liquids on streets and occupied areas I found the dry trash was difficult to wet with water without a surfactant but that it readily absorbed oily materials. That the natural oils and waxes contained in the gin trash or debris repelled the absorption of water enabling the mass to float while the plant debris soaked up the oil film effectively and preferentially removing most, if not all, of the surface film from the water. The plant debris, with its oil content may be biodegraded in situ and need not be removed from the water for further disposal.
When cotton is harvested in the United States a mechanical cotton picker traverses the field gathering the seed by beth mechanical and vacuum equipment. The vacuum process automatically collects a small amount of soil, even small stones. Lint cleaners at the gin remove most of the soil disposing of it in the trash. If a small sample of the dry gin trash (12 to 15% moisture content) be placed in water and the water examined microscopically every few hours one will find active microorganisms cruising about after 16 to 18 hours even though the gin trash has been in dry storage for over three years. Within 24 to 48 hours a very large population of microorganisms will be active in the water. These microorganisms came from cotton field soil and feed on the 16 percent protein, along with the many carbohydrates present in the cotton gin trash plant debris. This vast population of indigenous soil inhabiting microorganisms in the presence of water and petroleum hydrocarbons, benzene, toluene and xylenes, for example, has been used to biodegrade more than 20 hazardous substances, repeatedly. See U.S. Pat. No. 5,100,455, incorporated by reference.
A review of the technical literature discloses that as early as 1950 indigenous soil and sea water inhabiting microorganisms were observed biodegrading petroleum hydrocarbons. Many of the oil degrading organisms were specifically identified (ZoBell C., Assimilation of hydrocarbons by microorganisms. Scripps Institution of Oceanography, Univ. Calif., New Series No. 438, pages 479-481. 1950). The early reports by ZoBell reveal that petroleum hydrocarbons provide excellent sources of food and energy for a large number of soil inhabiting microorganisms capable of mineralizing oils and grease within a few days if water and mineral salts are available at favorable temperatures. Because cotton gin trash, itself, contains an oil and wax enabling it to repel absorption of water, and absorb oil while floating, and because the gin trash also carries a large number of the soil's indigenous microorganisms that utilize oils as a source of food and energy an ideal environment is provided for processed cotton gin trash to cleanse water surfaces of oil spills.
A review of the U.S. Patent literature discloses the following information:
U.S. Pat. No. 3,771,653, issued to J.P. Harnett, Nov. 13, 1973, discloses the use of a compost prepared by the bacterial digestion of organic waste material. I have tried Harnett's method of adding composted organic waste to an oil film floating on water. Some of the compost sinks without absorbing much oil. Furthermore, no mention is made of cotton gin trash in this patent although cotton gin trash is composed of about half organic waste and half mineral soil.
U.S. Pat. No. 3,791,990, issued to K. O. P. Fischer, Feb. 12, 1974, makes no mention of cotton gin trash although Fischer discusses removal of oil from water.
U.S. Pat. No. 3,902,998, issued to L. E. Bertram, Sep. 2, 1975, discloses the use of rice hulls to remove oil from water surfaces but makes no mention of cotton gin trash for the above purpose.
U.S. Pat. No. 4,102,783, issued to A. Zenno, et al., Jul. 25, 1978. This patent discloses the use of "unrefined cotton lints" and "unrefined cotton linters" for absorbing oils from both fresh and sea water. This patent does not mention the use of cotton gin trash although it mentions "using the waste cotton formed in a cotton spinning step" (Page 4, lines 52 and 53). Such waste cotton is different from cotton gin trash which contains about 45 percent inorganic soil particles along with other plant debris. Cotton gin trash contains no cotton lints or cotton linters except by accident. Both cotton lints and linters are made from reginned cottonseed. Again, no mention is made by Zenno, et al., of the use of cotton gin trash for absorbing oils from water. His mention of "lints" and "linters" refers to short fibers obtained from the spinning of cotton by mills producing fabric.
U.S. Pat. No. 4,832,852, issued to G. G. Wells, et al., May 23, 1989, discloses the fabrication of a mat of cotton waste fibers to absorb oil on water surfaces. The waste fibers were those obtained by reginning cottonseed as referred to by Zenno, et al., as "unrefined lints and linters." Again, no mention is made of cotton gin trash.
U.S. Pat. No. 4,925,343, issuedto R. L. Raible, et al., May 15, 1990, discloses a mixture of wood fibers and cotton linters to absorb oil from land or water. The linters were obtained from the reginning of cottonseed as mentioneed by Wells, et al., and Zenno, et al. No mention is made of the use of cotton gin trash.
U.S. Pat. No. 5,009,790, issued to M. R. Bustamante, et al., Apr. 23, 1991, discloses the use of kelp residue for cleansing water of oils. As in the above patents no mention is made of cotton gin trash and neither does this have any bearing on my patent.
In none of the above patents is cotton gin trash mentioned. Perhaps I should emphasize, again, that cotton gin trash is the residue remaining from the factory separation of cottonseed from its lint by a cotton gin and that cotton lints and linters are very short fibers removed from seed by reginning. Because the mechanical cotton picker is not selective it gathers everything within its reach, including some soil, sending it all to a gin. The gin separates the lint from the seed, cleansing both of soil and plant debris which the gin sends to a trash pile. The trash may not be incinerated because of the clean air act. It may not be fed to livestock because of poisonous chemicals used as harvest aids. It may not be returned to the land because of noxious grass and weed seeds and because much of the trash may carry harmful insects. My method of processing cotton gin trash, disclosed herein, destroys the above unwanted insects, weed and grass seeds and thereby converts a useless hazardous waste to a valuable commodity.